The present invention relates to connection means for interconnecting two duct elements.
By way of example, such connection means are designed to be used in circuits for fluid under pressure, for interconnecting two circuit elements, such as pipes, or a pipe and a functional member for transmitting or receiving fluid.
Connection devices are known for interconnecting two pipes, said devices comprising a connection piece formed by a tubular body having two ends, each for receiving one end of a respective pipe which is designed to be inserted into the connection piece. The connection device also comprises two sleeves, each screwed onto a respective end of the tubular body so as to deform a claw washer, between an inner shoulder of the sleeve and the outside of the tubular body, the claw washer passing from a state in which the pipe can pass freely therethrough, to a state in which the pipe is held in place. The axial positioning of the pipes inside the tubular body is generally ensured by means of annular shoulders arranged in the tubular body so as to form abutments preventing the pipes from being driven further into the connection piece.
In another embodiment, the connection means comprise a sleeve divided into first and second portions in axial succession provided with means for providing leaktight and releasable connection between said portions and the end of the tubular body and the end of the pipe respectively, and a removable abutment ring provided with means for locking it axially on the pipe at a distance from the end of said pipe so as to constitute both an abutment shoulder preventing the pipe from being driven further into the tubular body and an axial abutment shoulder between the second portion of the sleeve and the pipe.
Connection means also exist comprising a tubular connection member for connecting duct ends, which member is constituted by a pair of half-bodies arranged so as to be closed on at least one duct end. The pair of half-bodies is associated with means for gripping said duct end when the pair of half-bodies is closed on said duct end. The gripping means comprise teeth for penetrating into the duct ends, and/or abutment shoulders for cooperating either with setbacks formed in the duct ends, or with elements fitted on the duct ends.
Documents DE-A-967 249, CH-A-405 838, CH-A-677 395, WO-A-01/81811, and WO-A-98/46926, in particular, disclose connection means of the above type, but having gripping means comprising at least an outwardly-directed projection formed by plastic deformation of the duct end in a position set back from an end face of said duct end, and two inner shoulders of at least one of the half-bodies that are spaced apart axially so as to receive the outwardly-directed projection between them. The outwardly-directed projection made by plastic deformation of the duct end can be made in particular on site as a result of its simplicity and of the small number of means to be implemented, in particular after the duct end has been cut to length. The connection is then made by laterally engaging the half-bodies on the duct end in such a manner that the inner shoulders of the pair of half-bodies bracket the outwardly-directed projection. In that type of device, it is relatively difficult to put effective sealing means into place and to hold them there.
An object of the invention is to propose connection means of the above-mentioned type including effective and reliable sealing means.
To this end, the invention provides connection means for interconnecting two duct ends, the means comprising a tubular connection member for uniting the duct ends, the tubular member comprising at least one pair of half-bodies which is arranged so as to be closed on at least one duct end, at least one of the half-bodies including two inner shoulders that are spaced apart axially so as to receive therebetween an outwardly-directed projection formed by plastic deformation of the duct end in a position set back from an end face of said duct end, the means further comprising a sealing sub-assembly including a bushing defining a housing for receiving a zone of the duct end, which zone is adjacent to the end face of said duct end, and an annular gasket projecting into an annular cavity of said housing, the annular cavity being defined laterally by an inner shoulder of the bushing and a face of a ring received to slide in the bushing and having an opposite face that forms a ramp projecting from the bushing so as to co-operate with an inside surface of corresponding shape of at least one of the half-bodies.
This facilitates handling of the sealing gasket, protects it during handling, and enables the sealing gasket to be held in place during assembly, thereby ensuring good positioning thereof relative to the duct end. As a result, the risks of leakage due to the gasket being badly assembled are limited. When the pair of half-bodies is closed on the duct end, the inside surface of the half-body pushes the ring which compresses the gasket against the inner shoulder of the bushing in such a manner that the gasket is deformed radially at least a little, which improves the contact between said gasket and the outside surface of the duct end.
The inner shoulder of the bushing is preferably tapered.
When the gasket is pressed against the shoulder by the ring, the above-mentioned shape of the shoulder tends to cause the sealing gasket to move radially inwards so as to press the gasket against the duct end.
According to a particular characteristic, the half-bodies overlap the two duct ends, and preferably each duct end includes an outwardly-directed projection, and the pair of half-bodies has two inner shoulders for co-operating with the outwardly-directed projection of each duct end.
The connection member is thus formed by the pair of half-bodies. As a result, the number of parts for the connection means is particularly small.
Other characteristics and advantages of the invention appear on reading the following description of particular non-limiting embodiments of the invention.